From M.D. Anderson Cancer Center, Houston (R.K.M., G.H.); Peter MacCallum Cancer Centre, Melbourne, VIC, Australia (S. Loi); the Royal Marsden NHS Foundation Trust, London (A.O.), and Edinburgh Cancer Research Centre, Edinburgh (D.C.) - both in the United Kingdom; Winship Cancer Institute, Atlanta (E.P.); Sarah Cannon Research Institute/Tennessee Oncology-Nashville (E.H.) and Vanderbilt University Medical Center (V.A.), Nashville; University of California, Los Angeles, Medical Center-Jonsson Comprehensive Cancer Center, Los Angeles (S.A.H., D.S.), and Stanford Comprehensive Cancer Institute, Palo Alto (M.P.) - both in California; Dana-Farber Cancer Institute, Boston (N.U.L., I.K., E.P.W.); University of Colorado Cancer Center, Aurora (V.B.); Duke Cancer Institute, Durham (C.A.), and University of North Carolina Lineberger Comprehensive Cancer Center, Chapel Hill (L.A.C.) - both in North Carolina; University Health Network, Princess Margaret Cancer Centre, Toronto (P.L.B.), and British Columbia Cancer, Vancouver (K.G.) - both in Canada; Hospital Universitario Vall D'Hebron, Barcelona (M.O.); Sygehus Lillebaelt-Vejle Sygehus, Vejle, Denmark (E.J.); Centre Léon Bérard, Lyon, France (T.B.); Rambam Health Care Campus, Haifa, Israel (S.S.S.); Universitaetsklinikum Hamburg-Eppendorf, Hamburg (V.M.), and German Breast Group, Neu-Isenburg (S. Loibl) - both in Germany; Hospital Cuf Descobertas R. Mário Botas, Lisbon, Portugal (S.B.); Cliniques Universitaires Saint-Luc, Brussels (F.P.D.); Third Medical Department, Paracelsus Medical University Salzburg, Salzburg Cancer Research Institute-Center for Clinical Cancer and Immunology Trials, and Cancer Cluster Salzburg, Salzburg, Austria (R.G.); Istituto Europeo di Oncologia, IRCCS, University of Milan, Milan (G.C.); and Seattle Genetics, Bothell, WA (M.C.P.-W., L.W., W.F.).